If $a + b + c = -6$ and $x + y = -9$, what is $-7b - 6y - 7a - 6x - 7c$ ?
Solution: $= -7a - 7b - 7c - 6x - 6y$ $= (-7) \cdot (a + b + c) + (-6) \cdot (x + y)$ $= (-7) \cdot (-6) + (-6) \cdot (-9)$ $= 42 + 54$ $= 96$